epilepsy

Method for detecting of two different types of sleep spindles on electroencephalogram was offered. High precision of this method was demonstrated; it can be used in neurophysiological research of regularity of appearing of different patterns on electroencephalogram.

In the article we present an overview of a number of continuous wavelet transformbased techniques for analysis and diagnostic of oscillatory neuronal network activity of brain in experimentally obtained electroencephalographic data. We describe a technique for automatic detection of characteristic patterns for paroxysmal activity (spike-wave discharges) in epileptic electroencephalogram (EEG) based on wavelet spectrum power analysis, obtained with continuous wavelet transform with complex mother wavelet (Morlet) in specific frequency ranges.

The detailed wavelet analysis of sleep electric brain activity, obtained from rats with genetic predisposition to absence-epilepsy, has been performed. Characteristic features of time-and-frequency structure of sleep spindles (oscillatory pattern, that serve as electroencephalographic correlate for slow-wave sleep) have been discovered in long-term electroencephalographic data. Operation has been performed using continuous wavelet transform.

In the work the mathematical model of the thalamocortical network’s unit cell and it’s characteristic dynamical modes in system, describing the interaction between a thalamus, thalamus reticular nucleus and a cortex, is studied. During normal information processing, input signal gating occurs in time in the thalamo-cortical network. The violation of the normal functioning leads to an epilepsy, when the perception of information is disrupted.

In this paper we present the results of investigation of intermittent phase synchronization in a real neurophysiological system. This phenomenon is observed in different systems as well as near the boundaries of various types of chaotic synchronization. In the case of electroencephalogram (EEG) of the brain, chosen as a system under study, just the intermittent phase synchronization can indicate the existence and development of pathologies, for example, the presence of epileptic seizures.